Aircraft have openings in the outer surface of the empennage and/or fuselage for functional reasons. For example, windows or doors are provided within cutouts of the fuselage of an aircraft. Due to the cutouts in the otherwise smooth surface of the fuselage gaps, trenches, slits, furrows, lacunae, grooves or crevices may be present in the surface of the fuselage between adjoining cutout edges and edges of the components arranged within the cutout.
When airborne, such gaps tend to create turbulences in the airflow along the fuselage, which on one hand create additional noise and on the other hand additional drag, both of which are undesirable properties for an aircraft.
Document U.S. Pat. No. 2,104,144 A discloses an airplane door construction having a pneumatic tube sealing the juncture between a door of an aircraft and its respective frame.
Document U.S. Pat. No. 5,979,828 A discloses an apparatus for eliminating gaps in the doorframe of an aircraft that uses an elastomeric bladder which may be inflated with a pneumatic actuator.